Method of and apparatus for threading pipes.



F. P. McMlLLAN-. METHOD 0f AND APPARATUS FOR THREADlNG PIPES.

APPLICATION m n APR. 26. 1911.

Patented Oct. 16, 1917.

i iziza ZZZ-6278,

FRANK P. MOMILLAN, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T NATIONAL TUBE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

METHOD OF AND APPARATUS FOR THREADING PIPES.

Specification of Letters Patent.

Patented Oct. 1c, rem.

. Application filed April 26, 1917. Serial No. 184,753.

certain new and useful Improvements 1n Methods of and Apparatus for Threading Pipes, of which the following is a specification.

This invention relates to the art of pipe threading, and has for its object to prevent the accumulation of oil within the pipe and the consequent waste thereof.

Pipe threading apparatus as now commonly constructed employs bits or chasers for cutting threads on the exterior of a pipe, and it is the common practice to flood such bits or chasers with lubricating oil, a considerable portion of such oil, of course, entering the open end of the pipe and being when the latter and therefore is removed from ,the machine, such oil is wasted.

As above stated, the object of this invention is to prevent oil from entering the open end of the pipe during the threading operation of the machine, and this object is athereinafter more tained by closing or plugging the open end of the pipe in a very simple and efficient manner.

A further object of the invention is to effect the closing or plugging of the pipe in such a way as not to interfere with the usual operations of the threading machine and without reducing the output of the machine.

With these objects in view and others, the present invention consists in the combination and arrangement of parts, as will be the drawings, and particularly set forth in the appended claims, it being understood that changes in the form, proportion, size and minor details may be made, within the scope of the claims, without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawings,

Figure 1 is a sectional view taken through a threading die and a pipe to be threaded with the stopperor closure of the present invention shown in elevation.

Fig. 2 is an enlarged detail sectional view of the stopper or plug of the present invention.

Like characters of reference designate corfully described, shown in responding parts in each of the figures of the drawings.

For the purpose of illustrating the application and operation of the present invention, there has been shown in the accompanying drawings a portion 1 of the carriage of any ordinary or preferred form of screw threading machine. Secured to one face of this carriage is a threading die 2, including bits or chasers 3 which are capable of being adjusted radially in any common or preferred manner. The carriage 1 is provided with an opening 4 with which is alined the opening 5 through the die 2. The bits or chasers 3, of course, project into the opening- 5, and the tube 6 to be threaded is received between the bits or chasers 3 within which the tube or pipe is rotated, as usual. The tube or pipe is gripped between a pair of revolving jaws 7 of any common or preferred type for the purpose of rotating the pipe in contact with the bits or chasers which are gradually fed longitudinally of the-pipe by an advancing movement of the carriage. It seems unnecessary to illustrate the threading die in detail and the means for advancing the carriage, and therefore these old and well known features have not been illustrated in the drawing.

In carrying out the present invention, there is provided a stem or mandrel 8 having one end fixed to a stationary part 9 of the screw threading machine. It is preferred to have this stem adjustable in an endwise direction. One way of accomplishing rod threaded as at 10 and extending through an opening 11 in the part 9, there being nuts 12 upon the threaded stem portion and at opposite sides of the part 9, whereby the stem may be held in a rigid position and also adjusted longitudinally. The other end portion of the stem extends through the alined openings 4 and 5 of the carriage 1 and the die 2. A suitable reducer 13 is fitted in the opening 4 in the carriage and this reducer has anopening 14 of a size and shape to receive the stem 8 and at the same time permit of the necessary travel of the carriage back and forth in a direction 1ongitudinally of the stem.

On the forward end of the stem is the lug or closure proper, which consists of a shank 15suitably secured to the forward end of the stem 8, preferably by having the latter fitted into a threaded socket in the rear end of the shank. A spindle 16 extends forwardly from the center of the shank 15 and carries thereon a rotatable sleeve 17 which is externally threaded and is provided at its inner end with an external flange 18 bearing against the front end of the shank 15. One or more washers 19 of suitable material, say for instance, canvas, are placed upon the sleeve 17 and against the front side of the flange 18, where they areheld by a nut 20 fitted upon the threaded sleeve 17 A washer 21 is placed upon the outer end of the spindle 16 and against the outer ends of the sleeve 17 and the nut 20, and a split pin or key 21 extends through the forward end of the spindle and against the front side of the washer 21 so as to hold the latter in place, whereby the sleeve 17, nut 20 and is fed forwardly so as toengage the bits or chasers 3 with the exterior of the tube or pipe to cut screw threads thereon. As usual,

the bits or chasers are flooded with lubrieating oil,.and although the latter may accumulate around the open end of the tube or pipe, it cannot enter the latter, at least to any material extent, because of the presence of the closure or stopper, and therefore this excess oil may be collected, cleaned and re-used. After the threading operation has been performed, the bits or chasers are backed off from the tube or pipe, as usual, and then the carriage is retracted or withdrawn from the tube, whereupon the jaws 7 are released from the tube or pipe and the latter is'withdrawn from thestopper'. Any oil which may have accumulated in the outer end of the tube or pipe, outside of the washer 19, is, of course, wiped out of the tube when the latter is "pulled from the stopper.

To avoid wear between the periphery of the washer 19 and the interior of the tube or pipe, the washer isv of a diameter to fit snugly within thepipe so as to rotate'therewith. As the nut clamps the washer snugly against the flange 18, the composite plug made up of the sleeve 17, the nut 20 and the washer 19, rotates with the pipe and around the spindle 16.

When the washer has'become worn and liable to leak, it may be readily replaced by removal of the nut 20.

From the foregoing description of the inchine without altering or changing the latter in any manner whatsoever and without interfering with the' operation thereof or with the output of the machine, while at the same time waste of oil by being carried off with a tube or pipe that has been threaded, is effectively prevented. It will of course be understood that the stopper or closure may be used equally well with that type of threading apparatus wherein the die rotates and the tube or pipe remains stationary, as the diewould rotate around the stem 8 as an axis.

While the drawings illustrate external threading only, it is, of course, apparent that the invention is applicable to the cutting of interior threads, as the closure plug may be ositioned within a pipe beyond the inner imit of the screw threads to be cut, and when the cutting of the thread has beencompleted and the cutting apparatus removed from the pipe, the separation of thepipe and plug will result in wiping out the oil which has accumulated in the pipe during the cutting of the threads in exactly the same manner as when cutting external threads. It

will also be apparent that my invention is applicable to apparatus for cutting pipes to length as well as for cutting screw threads on the ends thereof.

Having thus described the invention, what I claim is 1. A pipe threading apparatus provided with means for effecting an oil-tight closure for the end of the tube or pipe being threaded to prevent the oil which is used on the cutting bits or chasers from accumulating within the tube or pipe at the inner side of the closure.

'2. A pipe threading apparatus provided with means to enter the end of a pipe and prevent the oil.'which enters said end of the pipe during the thread cutting operations from accumulating within the pipe at the inner side of the said means.

3. A pipe threadin apparatus provided with a closure plug or entering the adjacent open end of a pipe to. close the same with an oil-ti ht fit and prevent the oil employed on t e bits or chasers from accumulating within the tube or pipe at the inner side of the plug, and for wiping out of the tube or pipe such oil as may enter the tube or pipe in front of the plug.

4. A pipe threading apparatus including a threading die having bits or chasers, and a pipe closure supported axially with respect to the bits or chasers in position to engage and close with an oil-tight fit the open end of a pipe on which the bits or chasers are operated.

5. A pipe threading apparatus including a threading die having bits or chasers, and a pipe closure supported axially with respect to the bits or chasers inflposition to tube or pipe while engage and close the open end of a pipe on which the bits or chasers are operated, said pipe closure including a washer of greater diameter than the body of the closure and rotatable thereon.

6. A pipe threading apparatus including a threading die having bits or chasers, a pipe closure supported axially with respect to the bits or chasers in position to engage and close the open end of a pipe on which the bits or chasers are operated, said pipe closure including a spindle, an externally threaded sleeve rotatable thereon and provided with an annular flange, a nut on the threaded sleeve, and a washer clamped between the nut and the flange and of greater diameter than said members.

7. In a pipe threading apparatus, the combination with a carria e having a threading die provided with bits or chasers, said die and carriage having alined openings disposed axially with respect to the bits or chasers, of a stem disposed axially with respect to the openings of the carriage and die and provided with a pipe closure disposed to coiiperate with the adjacent end of a tube or pipe on which the bits or chasers are operating, said closure being of a character to have an oil-tight .fit with the open end of the tube or pipe being threaded to prevent oil from passing the closure and accumulating within the pipe at the inner side of the closure.

8. in a pipe threading apparatus, the combination of a carriage and a threading die carried thereby and provided with bits or chasers, the carriage and die having alined openings disposed axially with respect to the bits or chasers, of a stem extending through the alined openings and supported by a stationary part of the apparatus, and a pipe closure carried by the stem and disposed to cooperate with the adjacent open end of a tube or pipe on which the bits or chasers are operating, said closure being of a character to have an oiltight fit with the open end of the tube or pipe being threaded to prevent oil from passing the closure and accumulating within the pipe at the inner side of the closure.

9. Means for closing the open end of a being out, which consists of a stem for'the support of the device and provided with a spindle, a sleeve rotatable upon the spindle and provided with an annular flange, a nut on the sleeve, and a washer clamped between the nut and the flange and of greater diameter than the nut and flange.

10. A pipe threading apparatus including a threading die having bits or chasers, means for rotating a pipe in engagement with the bits or chasers, and a pipe closure plug supported axially with respect to the bits or chasers and in position to enter the pipe adjacent the open end thereof and of a size to have an oil-tight fit within the pipe, whereby such oil as may accumulate within the pipe outside of the plug will be wiped out of the pipe when the latter is removed endwise from the plug.

11. A pipe threading apparatus including a threading die having bits or chasers mounted upona reciprocating carriage, means to rotate a pipe in engagement with the bits or chasers, and a pipe closure plug supported axially with respect to the threading die and in position to enter the pipe adjacent the open end thereof and of a size to have an oil-tight fit within the pipe, substantially as and for the purpose described.

12. A pipe threading apparatus including a threading die having bits or chasers, and means to wipe accumulated oil from the interior of the pipe by the operation of separating the threaded pipe and the threading apparatus.

-13. A pipe threading apparatus including a threading die having bits or chasers, means for rotating a pipe in enga ement with the bits or chasers, means for e ecting separation of thethreaded pipe and the die in the longitudinal direction of the ipe,

and means to wipe accumulated oil from the interior of the pipe during the separation of the pipe and the die.

14. The herein described method which consists in cutting threads upon a pipe, flooding the cutting tool with oil, and closing the open end of the pipe to prevent the oil from accumulating within the pipe.

15. The herein described method WlllCll consists in cutting'threads upon a pipe, flooding the cutting tool with oil, applying a closure plug with an oil-tight fit within the end of the pipe which is adjacent the cutting tool, and separating the pipe and the closure plug in the longitudinal direction of the pipe to wipe out of the pipe such oil as may have accumulated therein outside of the closure plug.

16. The herein described method which consists in cutting threads upon a pipe, flooding the cutting tool with oil, applying a closure plug with an oil-tight fit within that end of the pipe which is adjacent the cutting tool, supporting the closure plug independently of the pipe, and withdi'awing the pipe endwise from the closure p 1%. The herein described method which consists in cutting threads upon a pipe, flooding the cutting tool with oil, separating the threaded pipe and the tool and simultaneously wiping out of the pipe such oil as has accumulated therein during the threading. operation.

18. The herein described method which consists in cutting threads upon a, pipe, of the pipe such; oil as may have accuniuflooding the cuttinghtool with Ollf, pllliggmg lated in front of the plug. the ipe against '0 e passage 0 0i at a, point? inwardly from the end of the pipe FRANK- MOMILLAE 5 which is being threaded, and separating In the presence of the pipe and the plug in the longitudinal Jos. E.-JACKWAN, direction of the pipe, thereby to wipe out CHAS. KALTENHAUSER. 

